Machine for grading leather blanks



Jan. 2, 1945. A. G. B. METCALF MACI-IlNE FOR GRADING LEATHER BLANKS Filed July 50, 1942 6 Sheets-Sheet l Jan. 2,1945 A. G; B. METCALF 3 2 MACHINE FOR GRADING LEATHER BLANKS ,Filed July 30, 1942 6 Sheets-Sheet 2 Jan.2, 1945. I A G, B, ME'TCALF 2,366.205

MACHINE FOR GRADING LEATHER BLANKS Filed July so, 1942 6 Sheets-Sheet s Jan. 2, 1945. A. G. B. .METCALF MACHINE FOR GRADING LEATHER BLANKS Filed July 30, 1942 6 Sheets-Sheet 4 BY V iINYENIyOR. )%1 M Jan. 2, 1945. A. G. B. METCALF MACHINE FOR GRADING LEATHER BLANKS Filed July so. 1942 e Sheets-sheaf, 5

a I INf EINTOR.

Jan..2, 1945. A. G. B. METCALF 2,366,205

MACHINE FOR GRADING LEATHER BLANKS 7 Filed July so, 1942 s Sheets-Sheet 6 %JMW.

Patented Jan, 2, 1945 UNITED STATES PATENT oFF cE mime FO G DmGQ -EATH R BEAN-KS Arthur B.- Metcalfi Milton, Mass:

Application-July. 30, 1942;;Serial Noz 452,931:

reclaims. Thisinventiontreiatesto machines for grading dledi-out: pieces or blanks ofv leathersuch as" shoe soles, taps and the like, as .by evening the same inraccordance with; the: thickness:- of: the :thinnest part: thereof as detected by. the measuring mechanismmfthe machine:

.Although .not} limited thereto; the invention. is partibularlytapplicable' tonthezwell known: Nichols grading: machines; of the: class shown:. and do scribedzzin the Nichols Ratent: Not 1357358.; and will be) described :1. in cohnectiom with a1. machine ofethiskindl l i 1 The" presentf invention' hasaitsx inception in the discovery that'the linear; speed at which the measuring: of leather. or; leather blanks" Cfil'lifb Inftheaccompanying drawings;

l Figure 1. isra partial;siderelevatiomof an ing and. grading: machinelembodyjngw; this inven- -tion,. said machine; being-riot their type.- shown? and described the :N-ichols patent ireferredvto' above.

-. l Figure 2 is aapartiah elevation of :the machine of Fig: l. as viewed; from the: opposite side thereof. Figure 3 is iarcentral longitudinalusectional .view

of: the machinershown .ineFigsa 11 and 2.; n

Figure .4: is alplan viewiofanievening'and grad ingrzmachi'n'e embodying; alternative? form of referred: to i cannot be' substantially increased'ibeyondiaJpredeteIminBd upper. limit peculiar'to. the

measuring mechanism and depending upon. the

thickness: of" the blanks being operated? upon;

without: impairing? the accuracy of measurement,

It has, also been 1 discovered thatthe quality of the skiving= or evening performed on .theblank and the conditionsmnder: whichthe; knife of. the machine operates; are greatly improved when the 'Iinear speed or: the blank: while being skived or evenedf is substantially" higher,- relatively, than.

the highest possible: linear" speed while it i is being. measuredi.

'I'herefcre;v fbr the purpose of increased producs tion=and1 improved skivin'gr or evening "effects, the presentinventionYhaswforr its? object: to provide a": grading machine wherein": this novel" and desirof the blank the invention; t a

Figure 5. is. av side; elevation ofythe machine slriow-zrrv in Fig.4; 1 i

ofr-thermachine shown int-Figs. hand 5.

FigureK'Z. is a: detail hereinafter-described.

The: illustrated-iembodiments-i; ofi the invention blade. 6 l;-. a continuously"actuatedwendlessi cater- Mile differential relationship. between the linear measuring: speedand the. linear skivingi speediof the-leather or leather: blank is maintained: while the machine isinioperation.'

To these ends the invention provides. an im proved methodof increasing. the: rate of' produc' tion or output: ofa grading machine of the class referred to: and simultaneously effecting 1 a superior: product; The-invention further provides means operativeiy;associated with the measuring and evening mechanisms; of a. machine of: the

class-described forvestazblishing and maintaining thiswnovel :differential speed relationshipvbetween the movementhftheblank throughthe" measuring mechanism; andv: it's imovementrv through. the skiving. or evening; mechanism; A. third: feature of; the" invention: provides for movement. or the Blanks; particularly short blanks; fromith'e meastiring: mechanism" to" the: evening mechanism" .of

theamachine at substantially greater speed than hasz heretofore beianipossihle; therehy'further in= creasinathezcutputq a pillar chain 1. conveyor; nam which theblanks are moved from ;.the.-x measuring mechanism. to

the *evening: mechanism; the usual. spring.

actuated rpresser bar. I281 disposed aboverand" cooperatively associated; with. the chain conveyor 124; and the usual'rblanbmarking mechanism including the'marking wheel. 44;;said evening; and

marking mechanisms: beingtregulated andv set for each blank. by the-= measuring-J mechanism: as usual; andthe operation .of'ytheimarking mechanism being automatically occasioned byth eveninsstmechanism .asiusuali. i

A1so;=, each 1 oil said: two: embodiments is provided': w? tihthetusualiw .fstart-measuring" trip mechanism including the blank-operated trip 1 member l22:. disp osed; between. the: measurin mechanism andithe eveninggmechanism; and with the: usual :gate: I 0.4- controlling the admission ofwblankstor-the machine-lana also forming. part 0B the. stopemeasuringi meohanisni of the.

machine;

The-conveyor= chain I'll-of eachflmachine ex+ V tends-around two t sprocket wheels: whereof. one is continuously driven in: aw-direetiontto move-the top-stretch toward; the-evenings mechanism.

it :In operating'. a machineiofl thisgtype. the blanks i even- Figure 6 is:- a partial;longitudinalisectiona11view are slid forwardly one at a timeon the usual table I08 and beneath gate I04, either automatically or by hand, so-as to cause its forward end to After being entered between the measuring or calipering rolls 2 and 3, the latter merely propel the blank forwardly unti1 the forward end thereof engages and lifts trip member I22 whereupon the latter acts through the usual devices to throw the start-measuring pawl H5 (Fig. 5)

ing upon the thickness of the blanks being operboth forms of the invention herein shown and that said mechanism is constructed as shown and described in said Nichols patent, said mechanism including the journal bearings 4 of roll 3 (Fig. 5),

yoke I3, lever 22, arm 26, rocker arm 29, shaft and the parts (not herein shown) which coninto action against ratchet wheel 3| where it U remains until trip member I22 drops off from the rear end of theblank. Before this last event, however, the gate I04 drops off from the rear end of the blank and acts through the usual devices to throw the stop-measuring pawl III (Fig. 5) into action against ratchet wheel '3I.

.The period of time between the raising of trip member I22 and the fall of gate I04 is the blankrneasuring interval during which the lower calipering roll 3 'follows the unevennesses of the blank and acts through the usual transmission including ratchet wheel 3I,'to set theevening mechanism and adjust marking wheel 44 in accordance with the thickness 'of the thinnest spot detected by roll 3 preparatory to the entrance of theblank between the feed rolls 42 and 60.

Thus, when the blank enters and passesbetween the fed rolls'42 and 60 the upward'displacement of roll is automatically limited'by, and-proportionate to,-the thickness of the thinnest spot as detected'by themeasuring mechanism, while the thicker parts of the blank will slightly depress the lower feed roll 60, the portion of the blank between the cutting edge of blade GI and the bottom of roll 42 being the evened blank which passes over blade BI and the portion of the blank below said'cutting edge being the removed shim or skiving, usually quite thin, which passes below the blade.

It is to be noted that when operating a maehinelof this kind the gate I04 is held 'in its 1 closed position to prevent the entrance of the next successive blank into the machine until the rear or trailing end of the preceding blank passes out from between the feed rolls 42 and 60 thereby permitting the upper feed roll'42 to drop and act through the usual connections 92, 89 and IM (Figs. 1 and 5) 'to open gate I04.

It is therefore evident that the rate of production of the machine, or the rate at which evened blanks can be discharged from the ma- I chine, is proportional to the length of time meas-' ured by the passage'of each blank from the rolls 2 and. 3' to and through the feed rolls 42 and B0.

In'machines of the Nichols class herein dis- 5 closed all four rolls 2'--3 and 4250 are usually of the same size, viz., about two and threesixteenths inches in diameter and owing mainly to the inertia of the parts of the transmission connecting the lower feeler roll 3 with the evennect shaft 30 with the slide 38 of the evening mechanism and with the wheel 44 of the marking mechanism but whichare shown in Fig. 4 of the Nichols patent as including the elements 32," 3'3, 35, 36, 31, 38 and 46. i "T i It is a purpose of this invention to'provide means whereby this production lag may be made substantially and desirably less than-heretofore while at the same time retaining the necessarily I I mediate gear I34 rotatably s'upportedbya stud shaft projecting from the frame of the machine. Gear I34 is compounded with a larger inter,-

-mediate gear I33 which is driven by a gear I32 fast on-the main shaft of the machine at one side of the latter. The ratiobetweenthe gears I34 and I35, as shown, is 2.21. Fast on main shaft 80 at the opposite side of the machine is a gear I32a (Fig. 1) acting through an intermediate gear I9 to drive a gear I39 provided on the upper feed roll 42. The lower feed roll- 60 is provided with a gear I38 driven by the gear I32 (Fig. 2). The pitch diameters of the gears I32, I32a; and 19 are alike and the pitch diameters of the gears I33, I38and I39 are also alike. It will therefore be clear that the three gears I33, I38 and I39 are driven atone speed and.that because of the ratio between the gears I34 and I35 the feed rolls 42 and 60 are drivenat twice the speed of the measuring rolls 2 and 3. Also. it will be clear that if the pair of rolls 2 and 3 are driven at the same speed as heretofore as herein-contemplated, then the feed rolls 42 and 60 will be driven twice as fast as-heretofore and twice as fast as the rolls 2 and 3. In this way each blank is propelled between the feed rolls 42 and 60 of the evening mechanism-at double the speed of the measuring rolls which not only results in a substantial saving. of time but also improves both the cutting effects and the conditions under which the knife operates.

The shaft of the lower feed rollBIl of the even ing mechanism carries the usual. sprocket I43 (Fig; 2) connected by a chain I40 with a sprocket I4I fast on the shaft I42 on which is fixedly mounted the usual chain-actuating-sprocket I4 m (Fig. 3). The pitch diameters of these three sprockets are such that the chain I24 is driven at the same speed as the surface. speed of the feed rol1s:*42-60u. Therefore; ,sincewbotlr feed rolls of the evening mechanism are driven; at double their formervspeed; theusame is truetof the chain con veyorvl 24; Consequently, the conveyor chain ad vances a each blank: from the measuring mechanisnr tor the evening mechanism at: double, its former. speed thus accomplishing a, further saving of' 'time; I i i I It is to'be noted that whil'e the blank is passing between the measuring rolls 2' and 3 with its forward end portion between presser'bar I23 and conveyor chain" I24, the engagement of the latter with the blank is frictional in character and so long: as" the blank is-=engagedby the measuring rolls the=latter grip said blank much more forcibly than: iS the= case with the presser bar and chain;

Therefore the blank speedwill bethat of the The blank progresses with this "increased" velo*- I city 'to and-between the feed-rolls 42 and BI! which forceithe same past'the knife GI and discharge it from the machine, the peripheral velocities of I said feedrollsbeing the sameaas the chain speed. 1 A's-the blank enters=between the feedrolls of the" evening-mechanism it lifts-'the"upperroll 42 to thelimit predetermined for it by the measuring mechanismy while the lowerfeed roll BlT-is' im mediatel'ythereafter depressed against the pressure of i its supporting springs to' the extent :of the thickness of the shinr that is removed from the blank by the knife.

As the evened blankils, discharged from-the machine by the feed rolls of the eveningmechanism the upper roll" 42 falls" into' its normal lowermost positionand acts through the connections 92 89 and "11- (Fig; 1') toswing gate Ill4upwardlyiinto its open position shown' in the drawings where it remains until the next blank is fed into position between the measuring rolls whereupon the depression ofr'the lowerro1l'3 trips the push ban IUI thereby-permitting the gate tofallinto position upon the entering blank;

In the embodimentoftheinvention illustrated in Figs; 4' to i 7, inclusive, the upper measuring roll 2:;iis providedwith a gear I (Figs. 4and 6) that is: driven by" an intermediate gear I34a which inturnisdrivenbya gears! fast on the main drive shaft 80: As' shown, the' pitch diameters of-"the-t'wo gears I35 and I34a are :both sixinches,

while-the pitch diameter of the main shaft, gear 8I is two inches. Thus three revolutions of the main shaftBfl imparts one revolution to the upper measuring roll 2. a

Also fast on the main shaft 88 is a four inch gear 82 which drives a six inch gear I38 faston the shaft of the lower feed roll of the evening mechanism, this ratio of the gears providing for two revolutions of gear I38 for each three revo1u-,

'tions of main shaft and gear 82.

the;gear?lagisaofithewsameasizevas its drlving gear' 833. It willrthus beclearrthat thei-upper feed roll 4220f: thewevening:mechanismxis (also rotated twice for. each: three. revolutions of the main drive shaft 80$ Inbthiswwaywthezfeed rolls'oftheevening mechanism: arewrotatedrtwice for each revolution ofrthe measuring rolls 2: andu3. Since the measuring rolls and the feed rolls are all of one size it will be clear that the blank propelling effects of the latter are twice thatloff the formeras is the casewith the; form" of "this invention illustrated in Figsal', 2 and 3'of the. drawings; l

The main shaftugear'83s (Fig; 5) is= driven by a gearfast; on a primezpower shaft? 86 r provided with tightlfiiflddODSE pulleys whereof one is shown amt;

In 1 this-form offtheiinvention the: chainoperating sprocket I4Ib (Figs. 6 and 7) has itshubtcon structed' with: over-running clutch, means 88 through which the shaft I42 normally drives-said sprocket at the same blanki-propelling speed as that: of measuring rol1s 2': and 3 but with provia sion fon accelerated forward movement of' the sprocketil 41b independently of shaftvl 42 as presently pointed out. carries a sprocket'93 (Figs. 4 and 6) connected'by axchain 94uwith a sprocketi95 that is compounded with the intermediategear I34a, said two sprockets=being of the same size. Thus; when the blank clears themeasuring rolls 2 and 3 it is trans ported to i the-rolls 42-60 3 of the evening mecha nismwby the conveyor chain I 24 at thesame speed as -that of the measuring 1 'rolls but immediately uporr entrance ofithe forward orleading end of the blank between-the rolls "42-450 of the evening mechanism whichare being" driven at twice the speed- Off. the measuring rolls" and chain, the

overrrunnihg 'clutch means of sprocket I 4 lb permits the chain I 24 andsprocket" Hill) to move Each blankpassed through thismachine of ing rolls 2-- and 3 at a relatively slow speed until itsiforward' end enters between' chain- I 24 and spring-pressed shoe" I23: then" fora period, of time; at the'same" relatively slow speed, by rolls 2 and 3 and chain I24 acting together upon' the blanmwithoutslippage-of the chain relatively to theblankaswiththeformofthe invention shown in-Eigs; 1; 2f.and"3; therr assoonas the rear end of theblank clears the rolls 2-and3', by chain I24 aione at the samevrel'atively slow speed as it is transferred'from the-measuring-rollsto the eveningzrolls; then" by feed-rol1s"42*60fat' twice its original speed for-a period-1 of time during which theover-runningclutch88 (Figs: 6 and 7)? permits the chain I24 to race ahead with theblank without sli'ppingrelativelythereto; and lastly; by feed rolls ta -so: alone by which the blank is carried past tl-ie knife anddischarged' from the machine,

the over-running clutch 88 permitting the shaft I42 to resume its drive of the chain at said original, or normal, relatively slow speed as soon as the rear end of the blank cleared said chain.

The above described novel constructions and modes of operation materially and desirably reduce the time consumed in passing each blank through the machine so that the successive blanks are fed into the machine more rapidly than heretofore.

By advancing the blank through the evening mechanism at double the speed formely employed, the present invention effects a decided improvement in the quality of skiving performed onthe blanks and, in addition, substantiallyincreases the output of the machine'as compared to the production rate of former machines of this class; at the same time, the improved machine retains the same high quality measuringcharacteristics which can only be accomplished when the measuring mechanism is operated at relatively low peed.

. What I claim is: l

1. A-leather grading machine of the class described having means for advancing each blank through the fields of action of the measuring mechanism and of the grading mechanism thereof, respectively, said blank-advancing means being operable to move each blank through the grading field at a substantially higher linear speed than it moves the blank through the measuring field.

'2. A leather grading machine of the class described having means for advancing each blank through the fields of action of the measuring mechanism and of the evening mechanism thereof, respectively, said blank-advancing means being operable to move each blank through the evening field at a substantially higher speed than it moves the blank through the measuring field,

3. A leather grading machine of the class described having means for advancing each blank through the fields of action of the measuring mechanism and of the evening mechanism thereof, respectively, said blank-advancing means being operable to movethe blank through the even.- ing field at a substantially higher linear speed than it moves'the blank through the measuring field; conveyor means for advancing each blank from the fieldof. action of the measuring mechanism to the field of action of the evening mechanism, and means for driving said conveyor means so-thatit'imparts a relatively greater speed to each blank-then the latter has while passing through the measuring field.

4. A grading machine of the class described having means for driving the evening mechanism thereof at a substantially greater blank-propelling speed than the blank-propelling speed of the measuring mechanism thereof.

5. A gradingmachine of the class described having means for driving the measuring and evening mechanisms thereof so that the evening mechanism is operated at a substantially greater blankveyor disposed between said mechanisms for delivering each measured blank to said evening mechanism, and means for driving said conveyor at a substantially greater blank-propelling speed than the blank-propelling speed of said measuring mechanism. I

6. A grading. machine of the class described having means for driving the measuring and grading mechanisms of said machine so that the grading mechanism is operated at asubstantially greater blank-propelling speed. than the blank propelling speed of said measuring mechanism; an endless conveyor disposed between said mechanisms for delivering each measured blank to said grading mechanism and means for driving said conveyor at a slower blank-propelling speed than the blank-propelling speed of said grading mechanism, said conveyor-driving means being constructed to permit acceleration of the speed of said conveyor by each blank While the latter is being propelled by the grading mechanism and is in engagement withsaid conveyor.

'7. A grading machine of the class described having means for driving the measuring and grading mechanisms thereof so that the grading mechanism is operated at a substantially greater blank-propelling speed than the blank-propelling speed of said measuring mechanism; an endless conveyor disposed between said mechanisms for deliverin each measured blank to said grading mechanism, and means for driving said conveyor at -a slower blank-propelling speed than; the blank-propelling speed of said grading mechanism, said conveyor-driving means including an over-running clutch for permitting acceleration of the speed of said conveyor by each blank while the latter is being propelled by the grading mechanism and said blank is in engagement with said conveyor. i

8. A grading machine of the class described having means for operating the measuring and grading mechanisms thereof; an endless conveyor disposedbetween said mechanisms for delivering each measured blank to said grading mechanism, and means for driving said conveyor at a substantially greater blank-propelling speed than the blank-propelling speed of said measuring mechanism. 'f i .9. A grading machine of the class described having a continuously rotating main shaft; measuring mechanism including a pair of calipering rolls; grading mechanism including a pair of feed mus; mechanism through which the main shaft continuously drives said calipering rolls of the measuring mechanism at a relatively low speed, and mechanism through which said main shaft continuously drives the feed rolls of the grading mechanism at a blank-propelling speed. that is substantially greater than theblank-propelling speed of said caliperin rolls;

10. The combination of claim 9 and wherein an endless conveyor is provided between said measuring and grading mechanisms for delivering each measured blank to said grading mechanism, and wherein means is provided for driving said conveyor at a substantially greater blank-propelling speed than the blank-propelling speed of said caliphering rolls.

ARTHUR G. B. METCALF. 

